Copper is an essential micronutrient that serves as a cofactor in numerous biological processes, but can be toxic when present in excess. Because of this, cells must tightly maintain copper levels. This includes balance between import and export of cellular copper. The major copper importer in humans is the high-affinity copper transporter SLC31A1 or CTR1. The localization of CTR1 varies between cell types, but is commonly found at the plasma membrane and intracellular vesicles [1-3].
